Digital Degradation

[skippybangkok]

Hey,

Have stored music in MP3 format for years, and notice bit by by songs get corupted, or errors in them, or fluctuating volumes. Has anyone noticed this. Not sure how to stop it

[MarkBKK]

Hey,

Have stored music in MP3 format for years, and notice bit by by songs get corupted, or errors in them, or fluctuating volumes. Has anyone noticed this. Not sure how to stop it

Er ... unless you have been copying them from medium to medium over the years and ignoring copy error messages (although that's highly unlikely, and would be a most improbable cause for what you describe), or have been constantly re-encoding the MP3 files (for example, changing bit rates), then either your hard disk is slowly disintegrating (equally unlikely) or the differences you are noticing are down to different players (which can handle errors differently) or maybe better speakers/headphones revealing problems that were there from the begining. (I had a problem with fluctuating volume once, but that was a hardware thing.)

A file is a file. If you copy it the copy is the same. They don't ''degrade'' over time. Random corruptions? Have you noticed any individual letters going missing or changing in old WP documents, or colours changing in old graphics files?

(Yes, I know that if you copy a file x billion times, you might, just might, drop the odd bit, but even that's unlikely.)

[phetaroi]

Er ... unless you have been copying them from medium to medium over the years and ignoring copy error messages (although that's highly unlikely, and would be a most improbable cause for what you describe), or have been constantly re-encoding the MP3 files (for example, changing bit rates), then either your hard disk is slowly disintegrating (equally unlikely) or the differences you are noticing are down to different players (which can handle errors differently) or maybe better speakers/headphones revealing problems that were there from the begining. (I had a problem with fluctuating volume once, but that was a hardware thing.)

A file is a file. If you copy it the copy is the same. They don't ''degrade'' over time. Random corruptions? Have you noticed any individual letters going missing or changing in old WP documents, or colours changing in old graphics files?

(Yes, I know that if you copy a file x billion times, you might, just might, drop the odd bit, but even that's unlikely.)

I think a lot depends on the storage medium. For many years it has been known that real compact discs do deteriorate over time and it does affect the quality of the music.

[MarkBKK]

Er ... unless you have been copying them from medium to medium over the years and ignoring copy error messages (although that's highly unlikely, and would be a most improbable cause for what you describe), or have been constantly re-encoding the MP3 files (for example, changing bit rates), then either your hard disk is slowly disintegrating (equally unlikely) or the differences you are noticing are down to different players (which can handle errors differently) or maybe better speakers/headphones revealing problems that were there from the begining. (I had a problem with fluctuating volume once, but that was a hardware thing.)

A file is a file. If you copy it the copy is the same. They don't ''degrade'' over time. Random corruptions? Have you noticed any individual letters going missing or changing in old WP documents, or colours changing in old graphics files?

(Yes, I know that if you copy a file x billion times, you might, just might, drop the odd bit, but even that's unlikely.)

I think a lot depends on the storage medium. For many years it has been known that real compact discs do deteriorate over time and it does affect the quality of the music.

All optical media can deteriorate over time, but things are very different with audio CDs (error correction, etc). I assumed the OP was referring to MP3 files.

[Beggar]

I think a lot depends on the storage medium. For many years it has been known that real compact discs do deteriorate over time and it does affect the quality of the music.

Don't forget the ears. They do not get better too over time :-)

[skippybangkok]

Nah....stored on my hard disk. have restored a few times from back ups. Pretty sure bad sectors which over the years have krept in.

Basically means all ur data over maybe 30 years or so will degrade? even on HDD's?

[OriginalPoster]

Nah....stored on my hard disk. have restored a few times from back ups. Pretty sure bad sectors which over the years have krept in.

Basically means all ur data over maybe 30 years or so will degrade? even on HDD's?

But wouldn't bad sectors cause CRC error messages to popup when copying the files from one drive to another? Is that happening?

[monty]

Nah....stored on my hard disk. have restored a few times from back ups. Pretty sure bad sectors which over the years have krept in.

Basically means all ur data over maybe 30 years or so will degrade? even on HDD's?

Normally not.

Digital files are different compared to analogue files.

A digital file either works, or it doesn't. Just one bit (0 or 1) with the wrong value will mess up things.

Now indeed there are error correction systems, but they AFAIK only work on uncompressed audio files (.wav) as the systems know the human ear won't hear a small error anyway. They ignore the error, and will even replace the wrong data with an educated guess of what it should be.

I'm not sure there is error correction on MP3 files, as they are basically files which are not played directly but have to go through an un-compressing algorithm first. I would guess a bad file would just freeze the song!

Possible though, as for example a slightly damaged DVD can still play, but green squares show up in the image when there is bad data. To big an error though and the dvd will simply freeze.

And indeed, copying files with errors in will normally result in an error message and a failed copy! Unless copying from the command line (or special program) which ignores errors and just copies what it reads.

But the above is assuming you use optical media, which is known to be error-prone (scratches, degradation over the years etc).

If you would have this kind of degradation on your hard disk, all other files should be affected as well, and they have most likely a zero tolerance level on errors. A program file with errors in will likely stop the program working altogether.

So you should start noticing operational problems on your PC, along with the "degraded" music!

[cdnvic]

Is it possible that you just got better speakers or a better sound card and now you notice flaws you hadn't before?

I can play mp3s on my computer and they sound just fine, but the flaws begin to show up when I play them in the truck on a much better sound system.

[Cuban]

If errors had occured in the stored data they would be found throughout the disk, therefore you would encounter file access problems, failure to read folders correctly and other IO failure messages - not just a sudden click of noise in the music section of a favored MP3 track.

------------------------------ what I used to tell non-techie people-------------------

".....you are getting these errors because you don't have a printer plugged into this big 25 way D type connector here at the back, what is happening is that the data fairies are attracted by the data dust that gathers on the floor under the empty connector, they are drawn into the computer and nibble away at the data on the hard disk."

[monty]

------------------------------ what I used to tell non-techie people-------------------

".....you are getting these errors because you don't have a printer plugged into this big 25 way D type connector here at the back, what is happening is that the data fairies are attracted by the data dust that gathers on the floor under the empty connector, they are drawn into the computer and nibble away at the data on the hard disk."

Did you perchance sell covers for 25 way D-type connectors :D

[Cuban]

No - but I did offer to use a magic sprinkle dust to ward off evil spirits that were attracted by the blue screen of death common in those days.

[skippybangkok]

Is it possible that you just got better speakers or a better sound card and now you notice flaws you hadn't before?

I can play mp3s on my computer and they sound just fine, but the flaws begin to show up when I play them in the truck on a much better sound system.

Easiest way to describe it , is like a scratch record skipping a few lines, or bouncing a bit. Am 100% sure it was never the case, as have had the songs for ages. It definately is a new error in the file.

[monty]

I am more starting to think it's your PC hicking up, messing with the decoding of the MP3 file.

Possible causes:

Antivirus accessing the same file at the same time.

Antivirus doing a full scan.

Another program demanding high read/write speeds of your hard drive (de-fragmenting, copying big files over to somewhere else, ...)

Another program making your PC go to 100% CPU cycle.

Try to open task manager (ctrl + alt + del) and see how many cpu is being used.

Also look at the hard disk light. Reading an MP3 file should make it only flash intermittently, if it is on continually or flashing very fast, something else is accessing the drive.

[skippybangkok]

good point....next time hear one, will listen to same song on iPhone. If windows issue, will not be repeated on iphone.

[rgs2001uk]

I am more starting to think it's your PC hicking up, messing with the decoding of the MP3 file.

Possible causes:

Antivirus accessing the same file at the same time.

Antivirus doing a full scan.

Another program demanding high read/write speeds of your hard drive (de-fragmenting, copying big files over to somewhere else, ...)

Another program making your PC go to 100% CPU cycle.

Try to open task manager (ctrl + alt + del) and see how many cpu is being used.

Also look at the hard disk light. Reading an MP3 file should make it only flash intermittently, if it is on continually or flashing very fast, something else is accessing the drive.

Agree with all the above, what other resources was the op using at the time.

I have found wmp to be one of the worst offenders, so much that I no longer have it on my computer.

Simple way for op to check, copy the song to another medium and play on another device.